Various types of motor parameter monitors such as load and speed indicators are known in the art. In general, these are of limited use since electric motors have many different characteristics that require special consideration. Thus, motors of the same ratings from different manufacturers usually have different operating characteristics. This means that it is very difficult to have universal monitors that accurately display the motor parameters.
Also, the matter of retrofitting motors in the field with monitors and detectors is difficult, and amounts to an economically insurmountable problem because of space limitations, access difficulties and the need for most electronic monitors to have wires connected thereto and for some to be incorporated into existing motor wiring for response to current flow, etc.
Furthermore, operating parameters vary with not only individual motor characteristics but also with applied temperatures and voltages so that it is difficult to provide precision measurements that hold over a wide range of motor operating characteristics. For example, the iron temperature and ambient temperature of a motor are different and can affect slip, current, torque, speed and other parameters. The same for changes of voltage to the motor.
There is no known prior art device that has successfully overcome all these problems, and thus limited use of motor parameter monitors has resulted.